The present invention relates to a closure device for controlling the flow of fluid through a conduit. More particularly, the invention relates to a valve which comprises both a poppet type closure member and a gate closure member which are actuated simultaneously to open and close the valve.
In flow completion systems for oil and gas wells, closure devices are often employed to isolate the conduits within various flow completion system components from the external environment. For example, a poppet type valve such as the male or female member of a conventional hydraulic coupling may be used to isolate a service and control conduit within a tubing hanger when the coupler is not engaged by a corresponding coupler on the tubing hanger running tool or the tubing spool. However, this type of closure device is prone to leakage and is therefore unreliable as a primary closure device.
One solution to this problem is to provide a second, more reliable closure device in the conduit. However, because of the space and weight limitations inherent in many flow completion system components, the use of two closure devices in a single conduit is often not possible. In addition, the second closure device typically must be actuated independently of the first closure device. This usually requires that the flow completion system component be provided with suitable conduits to communicate an actuating fluid to the second closure device, and this necessarily complicates the design of the flow completion system component.
In accordance with the present invention, these and other disadvantages in the prior art are overcome by providing a valve for controlling the flow of fluid through a component which includes a flow conduit extending therethrough, the valve comprising a first closure member for controlling the flow of fluid through the conduit, a second closure member for controlling the flow of fluid through the conduit, a valve stem which is connected to both the first and second closure members, and a spring for biasing the first and second closure members into a first position. The stem is responsive to an external force to move the first and second closure members from the first position to a second position. Moreover, one of the first and second positions corresponds to an open position of the valve, in which the fluid is permitted to flow through the conduit past both the first and second closure members, and the other position corresponds to a closed position of the valve, in which the fluid is blocked from flowing through the conduit by both the first and second closure members.
In one embodiment of the invention, the first closure member comprises a poppet head which is adapted to engage a corresponding poppet seat surrounding an opening that is in fluid communication with the conduit. In addition, the second closure member comprises a gate which is slidably positioned between a pair of seats which each comprise a through bore that is in fluid communication with the conduit. The valve preferably also comprises a valve bonnet which includes a male coupling portion that is adapted to connect with a female coupling member of a hydraulic coupler, and the valve stem comprises an actuating tip that is adapted to be engaged by a corresponding portion of the female coupling member to move the valve stem and thus the first and second closure members from the first position to the second position. In this manner, when the female coupling member is connected to the valve, the valve stem will actuate both the poppet closure member and the gate closure member to thereby open the conduit. Similarly, when female member is disconnected from the valve, the spring will return the poppet closure member and the gate closure member to the closed position to thereby seal the conduit.
Thus, the valve of the present invention provides two barriers between the conduit and the environment in a single device. Moreover, the second closure member is preferably a gate valve, which is recognized in the flow control industry as being a robust and reliable valve. In addition, since the first and second closure members are connected by the valve stem, the second closure member is actuated upon actuation of the first closure member. Consequently, no need exists for separate control signals to actuate the second closure member.
These and other objects and advantages of the present invention will be made apparent from the following detailed description, with reference to the accompanying drawings. In the drawings, the same reference numbers are used to denote similar components in the various embodiments.